Novel human calcium channels and related probes, cell lines and mehtods

ABSTRACT

Partial sequences for a novel mammalian (human and rat sequences identified) calcium channel subunit which we have labeled as the α 1I  subunit, and an additional novel human calcium channel which we have labeled as the α 1H  subunit are provided. Knowledge of the sequence of these two calcium channels permits the localization and recovery of the complete sequence from human cells, and the development of cell lines which express the novel calcium channels of the invention. These cells may be used for identifying compounds capable of acting as agonists or antagonists to the calcium channels.

[0001] This application is a regular application filed under 35 USC § 111 (a), claiming priority from U.S. Provisional Patent Application No. 60/039,204 filed Feb. 28, 1997.

TECHNICAL FIELD

[0002] The present invention relates to novel human calcium channel compositions, and to the expression of these compositions in cell lines for use in evaluating calcium channel function.

BACKGROUND OF THE INVENTION

[0003] The rapid entry of calcium into cells is mediated by a class of proteins called voltage-gated calcium channels. Calcium channels are a heterogeneous class of molecules that respond to depolarization by opening a calcium-selective pore through the plasma membrane. The entry of calcium into cells mediates a wide variety of cellular and physiological responses including excitation-contraction coupling, hormone secretion and gene expression. In neurons, calcium entry directly affects membrane potential and contributes to electrical properties such as excitability, repetitive firing patterns and pacemaker activity. Miller, R. J. (1987) Multiple calcium channels and neuronal function. Science 235:46-52. Calcium entry further affects neuronal functions by directly regulating calcium-dependent ion channels and modulating the activity of calcium-dependent enzymes such as protein kinase C and calmodulin-dependent protein kinase II. An increase in calcium concentration at the presynaptic nerve terminal triggers the release of neurotransmitter. Calcium entry also plays a role in neurite outgrowth and growth cone migration in developing neurons and has been implicated in long-term changes in neuronal activity. In addition to the variety of normal physiological functions mediated by calcium channels, they are also implicated in a number of human disorders. Recently, mutations identified in human and mouse calcium channel genes have been found to account for several disorders including, familial hemiplegic migraine, episodic ataxia type 2, cerebellar ataxia, absence epilepsy and seizures. Fletcher, C. F., Lutz, C. M., O'Sullivan, T. N., Shaughnessy, Jr., J. D., Hawkes, R., Frankel, W. N., Copeland, N. G. and Jenkins, N. A. (1996) Absence epilepsy in tottering mutant mice is associated with calcium channel defects. Cell 87:607-617; Burgess, D. L., Jones, J. M., Meiser, M. H. and Noebels, J. L. (1997) Mutation of the Ca2+channel β subunit gene Cchb4 is associated with ataxia and seizures in the lethargic (lh) mouse. Cell 88:385-392; Ophoff, R. A., Terwindt, G. M., Vergouwe, M. N., van Eijk, R., Oefner, P. J., Hoffman, S. M. G., Lamerdin, J. E., Mohrenweiser, H. W., Bulman, D. E., Ferrari, M., Haan, J., Lindhout, D., van Ommen, G. -J. B., Hofker, M. H., Ferrari, M. D. and Frants, R. R. (1996) Familial hemiplegic migraine and episodic ataxia type-2 are caused by mutations in the Ca2+channel gene CACNL1A4. cell 87:543-552; Zhuchenko, O., Bailey, J., Bonnen, P., Ashizawa, T., Stockton, D. W., Amos, C., Dobyns, W. B., Subramony, S. H., Zogbhbi, H. Y. and Lee, C. C. (1997) Autosomal dominat cerebellar ataxia (SCA6) associated with the small polyglutamine expansions in the α1A-voltage-dependent calcium channel. Nature Genetics 15:62-69. The clinical treatment of some disorders has been aided by the development of therapeutic calcium channel antagonists. Janis, R. J and Triggle, D. J. (1991) In Calcium Channels: Their Properties, Functions, Regulation and Clinical Relevance. CRC Press, London.

[0004] Native calcium channels have been classified by their electrophysiological and pharmacological properties as T, L, N, P and Q types (for reviews see McCleskey, E. W. and Schroeder, J. E. (1991) Functional properties of voltage-dependent calcium chnanels. Curr. Topics Membr. 39: 295-326, and Dunlap, K., Luebke, J. I. and Turner, T. J. (1995) Exocytotic Ca²⁺ channels in mammalian central neurons. Trends Neurosci. 18:89-98.). T-type (or low voltage-activated) channels describe a broad class of molecules that transiently activate at negative potentials and are highly sensitive to changes in resting potential. The L, N, P and Q-type channels activate at more positive potentials and display diverse kinetics and voltage-dependent properties. There is some overlap in biophysical properties of the high voltage-activated channels, consequently pharmacological profiles are useful to further distinguish them. L-type channels are sensitive to dihydropyridine (DHP) agonists and antagonists, N-type channels are blocked by the Conus geographus peptide toxin, ω-conotoxin GVIA, and P-type channels are blocked by the peptide ω-agatoxin IVA from the venom of the funnel web spider, Agelenopsis aperta. A fourth type of high voltage-activated Ca channel (Q-type) has been described, although whether the Q- and P-type channels are distinct molecular entities is controversial (Sather, W. A., Tanabe, T., Zhang, J. -F., Mori, Y., Adams, M. E., and Tsien, R. W. (1993) Distinctive biophysical and pharmacological properties of class A (B 1) calcium channel α1 subunits. Neuron 11: 291-303; Stea, A., Tomlinson, W. J., Soong, T. W., Bourinet, E., Dubel, S. J., Vincent, S. R and Snutch, T. P. (1994) Localization and functional properties of a rat brain α1A calcium channel reflect similarities to neuronal Q- and P-type channels. PNAS 91: 10576-10580.). Several types of calcium conductances do not fall neatly into any of the above categories and there is variability of properties even within a category suggesting that additional calcium channels subtypes remain to be classified.

[0005] Biochemical analyses show that neuronal calcium channels are heterooligomeric complexes consisting of three distinct subunits (α₁, α₂δ and β) (reveiwed by De Waard, M., Gurnett, C. A. and Campbell, K. P. (1997) In Ion Channels, Volume 4, edited by Narahashi, T. Plenum Press, New York). The α₁ subunit is the major pore-forming subunit and contains the voltage sensor and binding sites for calcium channel antagonists. The mainly extracellular α₂ is disulphide-linked to the transmembrane δ subunit and both are derived from the same gene and are proteolytically cleaved in vivo. The β subunit is a non-glycosylated, hydrophilic protein with a high affinity of binding to a cytoplasmic region of the α₁ subunit. A fourth subunit, γ, is unique to L-type Ca channels expressed in skeletal muscle T-tubules. The isolation and characterization of γ-subunit-encoding cDNAs is described in U.S. Pat. No. 5,386,025 which is incorporated herein by reference.

[0006] Molecular cloning has revealed the cDNA and corresponding amino acid sequences of six different types of α₁ subunits (α_(1A), α_(1B), α_(1C), α_(1D), α_(1E) and α_(1S)) and four types of β subunits (β₁, β₂, β₃ and β₄) (reviewed in Stea, A., Soong, T. W. and Snutch, T. P. (1994) Voltage-gated calcium channels. PCT Patent Publication WO 95/04144, which is incorporated herein by reference, discloses the sequence and expression of α_(1E) calcium channel subunits. In Handbook of Receptors and Channels. Edited by R. A. North, CRC Press.).

[0007] The different classes of (α1 and β subunits have been identified in different animals including, rat, rabbit and human and share a significant degree of amino acid conservation across species (for examples see: Castellano, A., Wei, X., Bimbaumer, L., and Perez-Reyes, E. (1993) Cloning and expression of a third calcium channel β subunit. J. Biol. Chem. 268: 3450-3455; Castellano, A., Wei, X., Bimbaumer, L., and Perez-Reyes, E. (1993) Cloning and expression of a neuronal calcium channel β subunit. J. Biol. Chem. 268: 12359-12366; Dubel, S. J., Starr, T. V. B., Hell, J., Ahlijanian, M. K., Enyeart, J. J., Catterall, W. A., and Snutch, T. P. (1992). Molecular cloning of the α₁ subunit of an co-conotoxin-sensitive calcium channel. Proc. Natl. Acad. Sci. USA 89: 5058-5062; Fujita, Y., Mynlieff, M., Dirksen, R. T., Kim, M., Niidome, T., Nakai, J., Friedrich, T., Iwabe, N., Miyata, T., Furuichi, T., Furutama, D., Mikoshiba, K., Mori, Y., and Beam, K. G. (1993) Primary structure and functional expression of the ω-conotoxin-sensitive N-type calcium channel from rabbit brain. Neuron 10: 585-598; Mikami, A., Imoto, K., Tanabe, T., Niidome, T., Mori, Y., Takeshima, H., Narumiya, S., and Numa, S. (1989). Primary structure and functional expression of the cardiac dihydropyridine-sensitive calcium channel. Nature 340: 230-233; Mori, Y., Friedrich, T., Kim, M. -S., Mikami, A., Nakai, J., Ruth, P., Bosse, E., Hofmann, F., Flockerzi, V., Furuichi, T., Mikoshiba, K., Imoto, K., Tanabe, T., and Numa, S. (1991) Primary structure and functional expression from complementary DNA of a brain calcium channel. Nature 350: 398-402; Perez-Reyes, E., Castellano, A., Kim, H. S., Bertrand, P., Baggstrom, E., Lacerda, A. E., Wei, X., and Bimbaumer, L. (1992). Cloning and expression of a cardiac/brain β subunit of the L-type calcium channel. S. Biol. Chem. 267: 1792-1797; Pragnell, M., Sakamoto, J., Jay, S. D., and Campbell, K. P. (1991). Cloning and tissue-specific expression of the brain calcium channel β-subunit. FEBS Lett. 291: 253-258; Snutch, T. P., Tomlinson, W. J., Leonard, J. P., and Gilbert, M. M. (1991) Distinct calcium channels are generated by alternative splicing and are differentially expressed in the mammalian CNS. Neuron 7: 45-57; Soong, T. W., Stea, A., Hodson, C. D., Dubel, S. J., Vincent, S. R., and Snutch, T. P. (1993) Structure and functional expression of a member of the low voltage-activated calcium channel family. Science 260: 1133-1136; Tomlinson, W. J., Stea, A., Bourinet, E., Charnet, P., Nargeot, J., and Snutch, T. P. (1993) Functional properties of a neuronal class C L-type channel. Neuropharmacology 32: 1117-1126; Williams, M. E., Feldman, D. H., McCue, A. F., Brenner, R., Velicelebi, G., Ellis, S. B., and Harpold, M. M. (1992) Structure and functional expression of α1, α2, and β subunits of a novel human neuronal calcium channel subtype. Neuron 8: 71-84; Williams, M. E., Brust, P. F., Feldman, D. H., Patthi, S., Simerson, S., Maroufi, A., McCue, A. F., Velicelebi, G., Ellis, S. B., and Harpold, M. (1992) Structure and functional expression of an Co-conotoxin-sensitive human N-type calcium channel. Science 257: 389-395.

[0008] In some expression systems the α₁ subunits alone can form functional calcium channels although their electrophysiological and pharmacological properties can be differentially modulated by coexpression with any of the four β subunits. Until recently, the reported modulatory affects of β subunit coexpression were to mainly alter kinetic and voltage-dependent properties. More recently it has been shown that β subunits also play crucial roles in modulating channel activity by protein kinase A, protein kinase C and direct G-protein interaction. (Bourinet, E., Charnet, P., Tomlinson, W. J., Stea, A., Snutch, T. P. and Nargeot, J. (1994) Voltage-dependent facilitation of a neuronal α1C L-type calcium channel. EMBO J. 13: 5032-5039; Stea, A., Soong, T. W. and Snutch, T. P. (1995) Determinants of PKC-dependent modulation of a family of neuronal calcium channels. Neuron 15:929-940; Bourinet, E., Soong, T. W., Stea, A. and Snutch, T. P. (1996) Determinants of the G-protein-dependent opioid modulation of neuronal calcium channels. Proc. Natl. Acad. Sci. (USA) 93: 1486-1491.)

[0009] The electrophysiological and pharmacological properties of the calcium channels cloned to date can be summarized as shown in Table 1. While the cloned α₁ subunits identified to date correspond to several of the calcium channels found in cells, they do not account for all types of calcium conductances described in native cells. For example, they do not account for the various properties described for the heterogenous family described as T-type calcium channels. Furthermore, they do not account for novel calcium channels described in cerebellar granule cells or other types of cells. (Forti, L. and Pietrobon, D. (1993) Functional diversity of L-type calcium channels in rat cerebellar neurons. Neuron 10: 437-450; Tottene, A., Moretti, A., Pietrobon, A. 1996. Functional diversity of P-type and R-type calcium channels in rat cerebellar neurons. J. Neurosci. 16: 6353-6363).

[0010] Because of the importance of calcium channels in cellular metabolism and human disease, it would be desirable to identify the remaining classes of α₁ subunits, and to develop expression systems for these subunits which would permit the study and characterization of these calcium channels, including the study of pharmacological modulators of calcium channel function. Thus, it is an object of the present invention to provide heretofor undisclosed calcium channels having novel α₁ subunits, including cell lines expressing these new calcium channels. It is a further object of the present invention to provide a method for testing these novel calcium channels using such cell lines. TABLE 1 ω-conotoxin 1,4- ω-agatoxin ω-conotoxin native GVIA dihydropyridines cadmium IVA MVIIC Ca²⁺ channel type α_(1A) — — ✓ ✓ ✓ P/Q-type α_(1B) ✓ — ✓ — ✓ N-type α_(1C) — ✓ ✓ — — L-type α_(1D) — ✓ ✓ — — L-type α_(1E) — — ✓ — — novel α_(1S) — ✓ ✓ — — L-type

SUMMARY OF THE INVENTION

[0011] The present invention provides partial sequences for a novel mammalian (human and rat sequences identified) calcium channel subunit which we have labeled as the α_(1I) subunit, and an additional novel human calcium channel which we have labeled as the α_(1H) subunit. This knowledge of the sequence of these two calcium channels permits the localization and recovery of the complete sequence from human cells, and the development of cell lines which express the novel calcium channels of the invention. These cells may be used for identifying compounds capable of acting as agonists or antagonists to the calcium channels.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 shows aligned amino acid sequences for the C. elegans C54D2.5 α₁ calcium channel subunit and initially identified portions of the calcium channel subunits of the invention.

DESCRIPTION OF THE INVENTION

[0013] The present invention includes the following aspects for which protection is sought:

[0014] (a) novel human calcium channel subunits and DNA fragments encoding such subunits. It will be appreciated that polymorphic variations may be made or may exist in the DNA of some individuals leading to minor deviations in the DNA or amino acids sequences from those shown which do not lead to any substantial alteration in the function of the calcium channel. Such variations, including variations which lead to substitutions of amino acids having similar properties are considered to be within the scope of the present invention.

[0015] (b) polynucleotide sequences useful as probes in screening human cDNA libraries for genes encoding these novel calcium channel subunits. These probes can also be used in histological assay to determine the tissue distribution of the novel calcium channel subunits.

[0016] (c) eukaryotic cell lines expressing the novel calcium channel subunits. These cell lines can be used to evaluate compounds as pharmacological modifiers of the function of the novel calcium channel subunits.

[0017] (d) a method for evaluating compounds as pharmacological modifiers of the function of the novel calcium channel subunits using the cell lines expressing those subunits alone or in combination with other calcium channel subunits.

[0018] Further, since defects in the novel calcium channel subunits may be associated with a human genetic disease including, but not limited to; epilepsy, migraine, ataxia, schizophrenia, hypertension, arrhythmia, angina, depression, small lung carcinoma, Lambert-Eaton syndrome, characterization of such associations and ultimately diagnosis of associated diseases can be carried out with probes which bind to the wild-type or defective forms of the novel calcium channels.

[0019] In accordance with the present invention, we have identified human DNA sequences which code for novel calcium channel α₁ subunits. These subunits are believed to represent two new types of α₁ subunits of human voltage-dependent calcium channels which have been designated as type α_(1I) and type α_(1H).

[0020] The novel α₁ subunits of the invention were identified by screening the C. elegans genomic DNA sequence data base for sequences homologous to previously identified mammalian calcium channel α₁ subunits. Specifically, the following twelve mammalian α₁ subunit sequences were used to screen the C. elegans genomic data bank:

[0021] rat brain α_(1A): GTCAAAACTC AGGCCTTCTA CTGG SEQ ID. No. 1

[0022] rat brain α_(1A): AACGTGTTCT TGGCTATCGC GGTG SEQ ID. No. 2

[0023] rat brain α_(1B): GTGAAAGCAC AGAGCTTCTA CTGG SEQ ID. No. 3

[0024] rat brain α_(1B): AACGTTTTCT TGGCCATTGC TGTG SEQ ID. No. 4

[0025] rat brain α_(1C): GTTAAATCCA ACGTCTTCTA CTGG SEQ ID. No. 5

[0026] rat brain α_(1C): AATGTGTTCT TGGCCATTGC GGTG SEQ ID. No. 6

[0027] rat brain α_(1D): GTGAAGTCTG TCACGTTTTA CTGG SEQ ID. No. 7

[0028] rat brain α_(1D): AAGCTCTTCT TGGCCATTGC TGTA SEQ ID. No. 8

[0029] rat brain α_(1E): GTCAAGTCGC AAGTGTTCTA CTGG SEQ ID. No. 9

[0030] rat brain α_(1E): AATGTATTCT TGGCTATCGC TGTG SEQ ID. No. 10

[0031] rat brain consensus #1: ATCTAYGCYR TSATYGGSAT G SEQ ID. No. 11

[0032] rat brain consensus #2: ATGGACAAYT TYGASTAYTC SEQ ID. No. 12

[0033] This search identified four distinct C. elegans cosmids that contain open reading frames (coding regions) that exhibit homology to mammalian calcium channel α₁ subunits:

[0034] cosmid and reading frame T02C5.5

[0035] cosmid and reading frame C48A7.1

[0036] cosmid and reading frame C54D2.5

[0037] cosmid and reading frame C27F2.3

[0038] Examination of the four C. elegans cosmid sequences by phylogeny analysis shows that two of these, T02C5.5 and C48A7.1, correspond closely with previously identified mammalian α₁ subunits. T02C5.5 appears to be an ancestral member related to the mammalian α_(1A), α_(1B) and α_(1E) subunits. C48A7.1 appears to be an ancestral member related to the mammalian L-type channels encoded by α_(1C), α_(1D) and α_(1S). In contrast, the C. elegans cosmids C54D2.5 and C27F2.3 identify novel types of calcium channel α₁ subunits distinct from the other mammalian subtypes.

[0039] Mammalian counterparts of the C. elegans calcium channel α₁ subunit encoded by C54D2.5 were identified by screening of the GenBank expressed sequence tag (EST) data bank. This analysis identified a total of 13 mammalian sequences that exhibit some degree of DNA sequence and amino acid identity to C54D2.5, of which 8 are human sequences. (Table 2) Three of these sequences appear unlikely to encode novel calcium channel subunits because they either exhibit a significant degree of homology to previously identified mammalian α₁ subunits (clones H06096 and H14053) or exhibit homology in a region not considered to be diagnostic of calcium channel α₁ subunits specifically as opposed to other types of ion channel molecules in general (clone D20469). The five remaining sequences (H55225, H55617, H55223, H55544, and F07776), however, are believed to encode two previously unidentified calcium channel α₁ subunits because the degree of amino acid identity closely matches that of known calcium channel subunits in conserved regions but is sufficiently different to indicate that they do not encode previously identified mammalian calcium channel α₁ subunits α_(1A), α_(1B), α_(1C), α_(1D), α_(1E), or α_(1S). The expected amino acid sequence closely matches but is not identical to amino acid sequences in these known calcium channel subunits. The aligned amino acids sequences are shown in FIG. 1. TABLE 2 Query = C54D2.5 CE02562 CALCIUM CHANNEL ALPHA-1 SUBUNIT LG:6 Database: Non-redundant Database of GenBank EST Division 824,500 sequences; 302,742,428 total letter Sequences producing High-scoring Segment Pairs: Frame Score P(N) gb|AA183990|AA183990 ms53e02.r1 Life Tech mouse embry . . . +1 108  1.8e-24 gb|H55225|H55225 CHR220164 Homo sapiens genomic c . . . +1 136  2.5e-10 db|D68412|CELK131B1F C.elegans cDNA clone yk131b1:5 . . . +3 117  1.7e-06 gb|R75128|R75128 MDB1075 Mouse brain, Stratagene . . . +3 113  7.2e-06 gb|H55617|H55617 CHR220556 Homo sapiens genomic c . . . +2 102  2.8e-05 emb|FO7776|HSC2HD061 H. sapiens partial CDNA sequence . . . +3 100  0.00057 gb|W76774|W76774 me84e08.rl Scares mouse embryo N . . . +2 98 0.0012 gb|H06096|E06096 y177e01.rl Homo sapiens cDNA clo . . . +3 98 0.0015 gb|H14053|H14053 ym65d10.r1 Homo sapiens cONA clo . . . +2 91 0.0036 gb|H55223|H55223 CHR220162 Homo sapiens genoinic c . . . +2 87 0.0039 dbj|D35703|CELK024D9F C. elegans cDNA clone yk24d9: 5′. . . +3 74 0.046 dbj|D20469|HUMGS01443 Human HL60 3′ directed MboI cDNA, . . . −2 66 0.91 gb|H55544|H55544 CHR220483 Homo sapiens genomic c . . . +1 65 0.98

[0040] Four of the five sequences (H55225, H55617, H55223, and H55544) are found on human chromosome 22, and are now believed to all be part of the same gene encoding the novel human calcium channel subunit all. The fifth sequence, F07776 is apparently distinct and associated with a further novel human calcium channel subunit designated O11H.

[0041] The sequences of the five selected sequences and the references from which they are taken are given as follows:

[0042] H55225 SOURCE human clone=C22_(—)207 primer=T3 library=Chromosome 22 exon Trofatter, et al., Genome Res. 5 (3): 214-224 (1995) SEQ ID No. 13 1 GTGATCACTC TGGAAGGCTG GGTGGAGATC ATGTACTACG TGATGGATGC TCACTCCTTC 61 TACAACTTCA TCTACTTCAT CCTGCTTATC ATACCCCTCT TGCCTTGCAC CCCATATGGT 121 CTTCCCAGAG TGAGCTCATC CACCTCGTCA TGCCTGACTC GACGTTCA

[0043] 1155617 SOURCE human clone=C22_(—)757 primer=T3 library=Chromosome 22 exon Trofatter, et al., Genome Res. 5 (3): 214-224 (1995) SEQ ID No. 14 1 GATGGTCGAG TACTCCCTGG ACCTTCAGAA CATCAALCCTG TCAGCCATCC GCACCGTGCG 61 CGTCCTGAGG CCCCTCAAAG CCATCAACCG CGTGCCCA

[0044] H55223 SOURCE human clone=C22_(—)204 primer=T3 library=Chromosome 22 exon Trofatter, et al, Genome Res. 5 (3): 214-224 (1995) SEQ ID No. 15 1 CATGCTGGTG ATCCTGCTGA ACTGCGTGAC ACTTGGCATG TACCAGCCGT GCGACGACAT 61 GGACTGCCTG TCCGACCGCT GCAAGATCCT GCAG

[0045] H55544 SOURCE human clone=C22_(—)651 primer=T3 library=Chromosome 22 exon Trofatter, et al, Genome Res. 5 (3): 214-224 (1995) SEQ ID No. 16 1 GTATCTCTGG TTACTTTAGT AGCCAACACT CTTGGCTACT CAGACCTTGG TCCCATTAA 61 TCCCTGCGAA CCTTGAGAGC ACTAAGACCT CTAAGAGCTT TGTCTAGATT TGAAGTAATG 121 AGG

[0046] F07776 SOURCE human. Submitted (Jan. 19, 1995) Genethon, B. P. 60, 91002 Evry Cedex France and Genetique Moleculaire et Biologie du developpement, CNRS UPR420 B. P. 8, 94801 Villejuif Cedex France E-mail: genexpress@genethon.fr SEQ ID No. 17 1 TTCTCTCCAT TGTAGGAATG TTTCTGGCTG AACTGATAGA AAAGTATTTT GTGTGCCCTA 61 CCCTGTTNCG AGTGATCCGT CTTGCCAGGA TTGGCCGAAT CCTACGTCTG ATCAAAGGAG 121 CAAAGGGGAT CCGCACGCTG CTCTTTGCTT TGATGATGTC CCTTCCTGCG TTGTTTAACA 181 TCGGNCTCCT TCTTTTCCTG GTCATGTTCA TCTACGNCAT CTTTGGGATG TCCAATTTTG 241 CCTATGTTAA GAGGGAAGTT GGGATCGATG ACATGTTNAN CTTTGAGACC TTTGGCAACA 301 GCATGATCTG CCTGTTCCAA ATTACAACCT CTGCTGGCTG GGA

[0047] A search of the Sanger Genome Sequencing Center (Cambridge, U.K.) and the Washington University Genome Sequencing Center (St. Louis. Mo.) sequences in progress revealed a Bacterial Artificial Chromosome (BAC) sequence (bK206c7) that contained matches to the C. elegans cosmid open reading frame, C54D2.5, and to the four human chromosome 22 ESTs, H55225, H55617, H55223,H55544. The C. elegans C54D2.5 cosmid sequence and the human EST sequences were then used to compare the translation of the bK206c7 BAC genomic sequence in all 6 reading frames. The analysis was performed using the graphical program Dotter (Eric Sohnhammer, NCBI). The analysis revealed a series of potential coding regions on one strand of the bK206c7 BAC sequence. These were subsequently translated in all 3 reading frames and the potential splice junctions identified. The translated sequence of this longer DNA fragment which is part of the human α_(1I) subunit gene is given by Seq. ID No. 18.

[0048] Using the sequence information from the five EST's, a full length gene can be recovered using any of several techniques. Polynucleotide probes having a sequence which corresponds to or hybridizes with the EST sequences or a distinctive portion thereof (for example oligonucleotide probes having a length of 18 to 100 nucleotides) can be used to probe a human cDNA library for identification of the full length DNA encoding the α_(1I) and α_(1H) subunits. The process of identifying cDNAs of interest using defined probes is well known in the art and is, for example, described in International Patent Publication No. WO95/04144, which is incorporated herein by reference. This process generally involves screening bacterial hosts (e.g. E. coli) harboring the library plasmids or infected with recombinant lambda phage with labeled probes, e.g. radiolabeled with ³²p, and selection of colonies or phage which bind the labeled probe. Each selected colony or phage is grown up, and the plasmids are recovered. Human cDNAs are recovered from the plasmids by restriction digestion, or can be amplified, for example by PCR. The recovered cDNA can be sequenced, and the position of the calcium channel subunit-encoding region further refined, although neither process is not necessary to the further use of the cDNA to produce cell lines expressing the novel calcium channel subunits.

[0049] Longer portions of DNA-encoding the novel calcium channel subunits of the invention can also be recovered by PCR cloning techniques using primers corresponding to or based upon the EST sequences. Using this technique to identify relevant sequences within a human brain total RNA preparation confirmed that the novel α_(1I) calcium channel subunit is present in human brain. Subcloning of the 567 nt PCR product and subsequent sequencing thereof showed that this product corresponds to the derived sequence form the bK206c7 BAC genomic sequence. The nucleotide sequence is given as SEQ ID No. 19. The same experiment was performed using a rat brain RNA preparation and resulted in recovery of a substantially identical PCR product. (SEQ ID. NO. 20). The protein encoded by the rat PCR product is 96% identical to the human PCR product.

[0050] These sequences, which presumably encode a partial subunit can be used as a basis for constructing full length human or rat a,, clones. Briefly, the subcloned α_(1I) PCR product is radiolabeled by random hexamer priming according to standard methods (See, Sambrook, J., Fritsch, E. F. and Maniatis, T. (1989) Molecular Cloning, A Laboratory Manual. Cold Spring Harbor Press) and used to screen commercial human brain cDNA libraries (Stratagene, La Jolla, Calif.). The screening of cDNA libraries follows standard methods and includes such protocols as infecting bacteria with recombinant lambda phage, immobilizing lambda DNA to nitrocellulose filters and screening under medium hybridization stringency conditions with radiolabeled probe. cDNA clones homologous to the probe are identified by autoradiography. Positive clones are purified by sequential rounds of screening.

[0051] Following this protocol, most purified cDNA's are likely to be partial sequence clones due the nature of the cDNA library synthesis. Full length clones are constructed from cDNA's which overlap in DNA sequence. Restriction enzyme sites which overlap between cDNAs are used to ligate the individual cDNA's to generate a full-length cDNA. For subsequent heterologous expression, the full-length cDNA is subcloned directly into an appropriate vertebrate expression vector, such as pcDNA-3 (Invitrogen, San Diego, Calif.) in which expression of the cDNA is under the control of a promoter such as the CMV major intermediate early promoter/enhancer. Other suitable expression vectors include, for example, pMT2, pRCICMV, pcDNA3.1 and pCEP4.

[0052] Once the full length cDNA is cloned into an expression vector, the vector is then transfected into a host cell for expression. Suitable host cells include Xenopus oocytes or mammalian cells such as human embryonic kidney cells as described in International Patent Publication No. WO 96/39512 which is incorporated herein by reference and Ltk cells as described in U.S. Pat. No. 5,386,025 which is incorporated herein by reference. Transfection into host cells may be accomplished by microinjection, lipofection, glycerol shock, electroporation calcium phosphate or particle-mediated gene transfer. The vector may also be transfected into host cells to provide coexpression of the novel α₁ subunits with a β and/or an α₂δ subunit.

[0053] The resulting cell lines expressing functional calcium channels including the novel α₁ subunits of the invention can be used test compounds for pharmacological activity with respect to these calcium channels. Thus, the cell lines are useful for screening compounds for pharmaceutical utility. Such screening can be carried out using several available methods for evaluation of the interaction, if any, between the test compound and the calcium channel. One such method involves the binding of radiolabeled agents that interact with the calcium channel and subsequent analysis of equilibrium binding measurements including but not limited to, on rates, off rates, K_(d) values and competitive binding by other molecules. Another such method involves the screening for the effects of compounds by electrophysiological assay whereby individual cells are impaled with a microelectrode and currents through the calcium channel are recorded before and after application of the compound of interest. Another method, high-throughput spectrophotometric assay, utilizes the loading the cell lines with a fluorescent dye sensitive to intracellular calcium concentration and subsequent examination of the effects of compounds on the ability of depolarization by potassium chloride or other means to alter intracellular calcium levels. Compounds to be tested as agonists or antagonists of the novel (α_(1I) and α_(1H) calcium channel subunits are combined with cells that are stably or transiently transformed with a DNA sequence encoding the α_(1I) or α_(1H) calcium channel subunits of the invention and monitored using one of these techniques.

[0054] DNA fragments with sequences given by SEQ ID Nos. 13-19 may also be used for mapping the distribution of α_(1I) and α_(1H) calcium channel subunits within a tissue sample. This method follows normal histological procedures using a nucleic acid probe, and generally involves the steps of exposing the tissue to a reagent comprising a directly or indirectly detectable label coupled to a selected DNA fragment, and detecting reagent that has bound to the tissue. Suitable labels include fluorescent labels, enzyme labels, chromophores and radio-labels.

EXAMPLE 1

[0055] In order to isolate novel human calcium channel α₁ subunits using standard molecular cloning protocols, synthetic DNA probes are prepared, radiolabeled with ³²P and utilized to screen human cDNA libraries commercially available in lambda phage vectors (Stratagene, La Jolla, Calif.) based on the human DNA sequences for H55225, H55617, H55223, H55544 and F07776. DNA fragments with the sequence of sequence ID NOs 18 and 19 may also be used for this purpose. Positive phage are purified through several rounds of screening involving immobilizing the phage DNA on nitrocellulose filters, hybridizing with the radiolabeled probe, washing off of excess probe and then selection of clones by autoradiography. Clones identified by this approach are expected to be partial length clones due to the nature of cDNA library synthesis and several rounds of screening for each calcium channel type may be necessary to obtain full-length clones.

[0056] To characterize the clones, double stranded plasmid DNA is prepared from the identified clones and the sequences are determined using 35S dATP, Sequenase and standard gel electrophoresis methods. Regions of similarity and regions of overlap are determined by comparison of each cDNA sequence.

[0057] Full-length clones are constructed by ligating overlapping cDNA fragments together at common restriction enzyme sites. The full-length clones are subsequently inserted into vectors suitable for expression in vertebrate cells (e.g. pMT2, pRC/CMV, pcDNA3.1, pCEP4, pREP7) by ligation into restriction sites in the vector polylinker region which is downstream of the promoter used to direct cDNA expression.

[0058] DNA encoding the novel calcium channels can be stably or transiently introduced into eukaryotic cells (e.g. human embryonic kidney, mouse L cells, chinese hamster ovary, etc) by any number of available standard methods. Stable transfection is achieved by growing the cells under conditions that promote growth of cells expressing a marker gene which is contained in the expression vector (e.g. dihydrofolate reductase, thymidine kinase, or the like). The heterologous DNA encoding the human calcium channel may be integrated into the genome or may be maintained as an episomal element.

[0059] Expression of the human calcium channel in transfected cells may monitored by any number of techniques, including Northern blot for RNA analysis, Southern blot for cDNA detection, electrophysiological assay for calcium channel function, the binding of radiolabeled agents thought to interact with the calcium channel, and fluorescent assay of dyes sensitive to intracellular calcium concentration.

EXAMPLE 2 Heterologous Expression of Human α_(1I) Calcium Channels in Cells

[0060] A. Transient Transfection in Mammalian Cells

[0061] Host cells, such as human embryonic kidney cells, HEK 293 (ATCC# CRL 1573) are grown in standard DMEM medium supplemented with 2 mM glutamine and 10% fetal bovine serum. HEK 293 cells are transfected by a standard calcium-phosphate-DNA co-precipitation method using the full-length human α_(1I) calcium channel cDNA in a vertebrate expression vector (for example see Current protocols in Molecular Biology). The human α_(1I) calcium channel cDNA may be transfected alone or in combination with other cloned subunits for mammalian calcium channels, such as α2δ and β subunits, and also with clones for marker proteins such the jellyfish green fluorescent protein.

[0062] Electrophysiological Recording: After an incubation period of from 24 to 72 hrs the culture medium is removed and replaced with external recording solution (see below). Whole cell patch clamp experiments are performed using an Axopatch 200B amplifier (Axon Instruments, Burlingame, Calif.) linked to an IBM compatible personal computer equipped with pCLAMP software. Microelectrodes are filled with 3 M CsCl and have typical resistances from 0.5 to 2.5 MΩ. The external recording solution is 20 mM BaCl₂, 1 mM MgCl₂, 10 mM HEPES, 40 mM TEACl, 10 mM Glucose, 65 mM CsCl, (pH 7.2). The internal pipette solution is 105 mM CsCl, 25 mM TEACl, 1 mM CaCl₂, 11 mM EGTA, 10 mM HEPES (pH 7.2). Currents are typically elicited from a holding potential of −100 mV to various test potentials. Data are filtered at 1 kHz and recorded directly on the harddrive of a personal computer. Leak subtraction is carried out on-line using a standard P/5 protocol. Currents are analyzed using pCLAMP versions 5.5 and 6.0. Macroscopic current-voltage relations are fitted with the equation I={1/(1+exp(−(V_(m)−V_(h))/S)}×G−(V_(m)−E_(rev)), where V_(m) is the test potential, V_(h) is the voltage at which half of the channels are activated, and S reflects the steepness of the activation curve and is an indication of the effective gating charge movement. Inactivation curves are normalized to 1 and fitted with I=(1/l+exp ((V_(m)−V_(h))/S) with V_(m) being the holding potential. Single channel recordings are performed in the cell-attached mode with the following pipette solution (in mM): 100 BaCl₂, 10 HEPES, pH 7.4 and bath solution: 100 KCl, 10 EGTA, 2 MgCl₂, 10 HEPES, pH 7.4.

[0063] B. Transient Transfection in Xenopus Oocytes

[0064] Stage V and VI Xenopus oocytes are prepared as described by Dascal et al (1986), Expression and modulation of voltage-gated calcium channels after RNA injection into Xenopus oocytes. Science 231:1147-1150. After enzymatic dissociation with collagenase, oocytes nuclei are microinjected with the human α_(1I) calcium channel cDNA expression vector construct (approximately 10 ng DNA per nucleus) using a Drummond nanoject apparatus. The human α_(1I) calcium channel may be injected alone, or in combination with other mammalian calcium channel subunit cDNAs, such as the α2-δ and β1b subunits. After incubation from 48 to 96 hrs macroscopic currents are recorded using a standard two microelectrode voltage-clamp (Axoclamp 2A, Axon Instruments, Burlingame, Calif.) in a bathing medium containing (in mM): 40 Ba(OH)₂, 25 TEA-OH, 25 NaOH, 2 CsOH, 5 HEPES (pH titrated to 7.3 with methan-sulfonic acid). Pipettes of typical resistance ranging from 0.5 to 1.5 mΩ are filled with 2.8M CsCl, 0.2M CsOH, 10 mM HEPES, 10 mM BAPTA free acid. Endogenous Ca (and Ba)—activated Cl currents are suppressed by systematically injecting 10-30 nl of a solution containing 100 mM BAPTA-free acid, 10 mM HEPES (pH titrated to 7.2 with CsOH) using a third pipette connected to a pneumatic injector. Leak currents and capacitive transients are subtracted using a standard P/5 procedure.

EXAMPLE 3 Construction of Stable Cell Lines Expressing Human α_(1I) Calcium Channels

[0065] Mammalian cell lines stably expressing human α_(1I) calcium channels are constructed by transfecting the α_(1I) calcium channel cDNA into mammalian cells such as HEK 293 and selecting for antibiotic resistance encoded for by an expression vector. Briefly, the full-length human α_(1I) calcium channel cDNA subcloned into a vertebrate expression vector with a selectable marker, such as the pcDNA3 (InvitroGen, San Diego, Calif.), is transfected into HEK 293 cells by calcium phosphate coprecipitation or lipofection or electroporation or other method according to well known procedures (Methods in Enzymology, Volume 185, Gene Expression Technology (1990) Edited by Goeddel, D. V.). The human α_(1I) calcium channel may be transfected alone, or in combination with other mammalian calcium channel subunit cDNAs, such as the α2-δ and β1b subunits, either in a similar expression vector or other type of vector using different selectable markers. After incubation for 2 days in nonselective conditions, the medium is supplemented with Geneticin (G418) at a concentration of between 600 to 800 ug/ml. After 3 to 4 weeks in this medium, cells which are resistant to G418 are visible and can be cloned as isolated colonies using standard cloning rings. After growing up each isolated colony to confluency to establish cell lines, the expression of human α_(1I) calcium channels can be determined at with standard gene expression methods such as Northern blotting, RNase protection and reverse-transcriptase PCR.

[0066] The functional detection of human α_(1I) calcium channels in stably transfected cells can be examined electrophysiologically, such as by whole patch clamp or single channel analysis (see above). Other means of detecting functional calcium channels include the use of radiolabeled ⁴⁵Ca uptake, fluorescence spectroscopy using calcium sensitive dyes such as FURA-2, and the binding or displacement of radiolabeled ligands that interact with the calcium channel.

1 33 1 24 DNA Rat 1 gtcaaaactc aggccttcta ctgg 24 2 24 DNA Rat 2 aacgtgttct tggctatcgc ggtg 24 3 24 DNA Rat 3 gtgaaagcac agagcttcta ctgg 24 4 24 DNA Rat 4 aacgttttct tggccattgc tgtg 24 5 24 DNA Rat 5 gttaaatcca acgtcttcta ctgg 24 6 24 DNA Rat 6 aatgtgttct tggccattgc ggtg 24 7 24 DNA Rat 7 gtgaagtctg tcacgtttta ctgg 24 8 24 DNA Rat 8 aagctcttct tggccattgc tgta 24 9 24 DNA Rat 9 gtcaagtcgc aagtgttcta ctgg 24 10 24 DNA Rat 10 aatgtattct tggctatcgc tgtg 24 11 21 DNA Rat 11 atctaygcyr tsatyggsat g 21 12 20 DNA Rat 12 atggacaayt tygastaytc 20 13 168 DNA Human Expressed sequence tag H55225 13 gtgatcactc tggaaggctg ggtggagatc atgtactacg tgatggatgc tcactccttc 60 tacaacttca tctacttcat cctgcttatc atacccctct tgccttgcac cccatatggt 120 cttcccagag tgagctcatc cacctcgtca tgcctgactc gacgttca 168 14 98 DNA Human Expressed sequence tag H55617 14 gatggtcgag tactccctgg accttcagaa catcaacctg tcagccatcc gcaccgtgcg 60 cgtcctgagg cccctcaaag ccatcaaccg cgtgccca 98 15 94 DNA Human Expressed sequence tag H55223 15 catgctggtg atcctgctga actgcgtgac acttggcatg taccagccgt gcgacgacat 60 ggactgcctg tccgaccgct gcaagatcct gcag 94 16 123 DNA Human Expressed sequence tag H55544 16 gtatctctgg ttactttagt agccaacact cttggctact cagaccttgg tcccattaaa 60 tccctgcgaa ccttgagagc actaagacct ctaagagctt tgtctagatt tgaaggaatg 120 agg 123 17 343 DNA Human Expressed sequence tag F07776 17 ttctctccat tgtaggaatg tttctggctg aactgataga aaagtatttt gtgtgcccta 60 ccctgttncg agtgatccgt cttgccagga ttggccgaat cctacgtctg atcaaaggag 120 caaaggggat ccgcacgctg ctctttgctt tgatgatgtc ccttcctgcg ttgtttaaca 180 tcggnctcct tcttttcctg gtcatgttca tctacgncat ctttgggatg tccaattttg 240 cctatgttaa gagggaagtt gggatcgatg acatgttnan ctttgagacc tttggcaaca 300 gcatgatctg cctgttccaa attacaacct ctgctggctg gga 343 18 5562 DNA Human CDS (1)...(5562) Human alpha-1 partial sequence from BAC bK206c7 18 atg ttt ttc gtc tca gcc aat ccc tgg gtg agt ttc acc agt ttt gat 48 Met Phe Phe Val Ser Ala Asn Pro Trp Val Ser Phe Thr Ser Phe Asp 1 5 10 15 tta aac gtg gcc aat atg gac aac ttc ttc gcc ccc gtt ttc acc atg 96 Leu Asn Val Ala Asn Met Asp Asn Phe Phe Ala Pro Val Phe Thr Met 20 25 30 ggc aaa tat tat acg caa ggc gac aag gtg ctg atg ccg ctg gcg att 144 Gly Lys Tyr Tyr Thr Gln Gly Asp Lys Val Leu Met Pro Leu Ala Ile 35 40 45 cag gct ctg aaa cag ctg atg ttc aaa ttg gtg gcc act gtt gct cga 192 Gln Ala Leu Lys Gln Leu Met Phe Lys Leu Val Ala Thr Val Ala Arg 50 55 60 aca cat gct aca ccg tca cac atc acg ggt ggt cct gga aca ggg atg 240 Thr His Ala Thr Pro Ser His Ile Thr Gly Gly Pro Gly Thr Gly Met 65 70 75 80 cac acg ggc acc ttc cag gaa gga gct gag cct ggt tca tct cag cac 288 His Thr Gly Thr Phe Gln Glu Gly Ala Glu Pro Gly Ser Ser Gln His 85 90 95 cct gag gca cag gcc acg tat aca gca ggg tgc acc cca gcc ccc acg 336 Pro Glu Ala Gln Ala Thr Tyr Thr Ala Gly Cys Thr Pro Ala Pro Thr 100 105 110 ggc gat ccc acc tgc tgc ttt gtc ctt gac ttg gtg tgc acg tgg ttt 384 Gly Asp Pro Thr Cys Cys Phe Val Leu Asp Leu Val Cys Thr Trp Phe 115 120 125 gaa tgt gtc agc atg ctg gtg atc ctg ctg aac tgc gtg aca ctt ggc 432 Glu Cys Val Ser Met Leu Val Ile Leu Leu Asn Cys Val Thr Leu Gly 130 135 140 atg tac cag ccg tgc gac gac atg gac tgc ctg tcc gac cgc tgc aag 480 Met Tyr Gln Pro Cys Asp Asp Met Asp Cys Leu Ser Asp Arg Cys Lys 145 150 155 160 atc ctg cag gtc ttt gat gac ttc atc ttt atc ttc ttt gcc atg gag 528 Ile Leu Gln Val Phe Asp Asp Phe Ile Phe Ile Phe Phe Ala Met Glu 165 170 175 atg gtg ctc aag atg gtg gcc ctg ggg att ttt ggc aag aag tgc tac 576 Met Val Leu Lys Met Val Ala Leu Gly Ile Phe Gly Lys Lys Cys Tyr 180 185 190 ctc ggg gac aca tgg aac cgc ctg gat ttc ttc atc gtc atg gca ggc 624 Leu Gly Asp Thr Trp Asn Arg Leu Asp Phe Phe Ile Val Met Ala Gly 195 200 205 aac atc aac ctg tca gcc atc cgc acc gtg cgc gtc ctg agg ccc ctc 672 Asn Ile Asn Leu Ser Ala Ile Arg Thr Val Arg Val Leu Arg Pro Leu 210 215 220 aaa gcc atc aac cgc gtg ccc agt atg cgg atc ctg gtg aac ctg ctc 720 Lys Ala Ile Asn Arg Val Pro Ser Met Arg Ile Leu Val Asn Leu Leu 225 230 235 240 ctg gac aca ctg ccc atg ctg ggg aat gtc ctg ctg ctc tgc ttc ttt 768 Leu Asp Thr Leu Pro Met Leu Gly Asn Val Leu Leu Leu Cys Phe Phe 245 250 255 gtc ttc ttc atc ttt ggc atc ata ggt gtg cag ctc tgg gcg ggc ctg 816 Val Phe Phe Ile Phe Gly Ile Ile Gly Val Gln Leu Trp Ala Gly Leu 260 265 270 ctg cgt aac cgc tgc ttc ctg gag gag aac ttc acc ata caa ggg gat 864 Leu Arg Asn Arg Cys Phe Leu Glu Glu Asn Phe Thr Ile Gln Gly Asp 275 280 285 gtg gcc ttg ccc cca tac tac cag ccg gag gag gat gat gag atg ccc 912 Val Ala Leu Pro Pro Tyr Tyr Gln Pro Glu Glu Asp Asp Glu Met Pro 290 295 300 ttc atc tgc tcc ctg tcg ggc gac aat ggg ata atg ggc tgc cat gag 960 Phe Ile Cys Ser Leu Ser Gly Asp Asn Gly Ile Met Gly Cys His Glu 305 310 315 320 atc ccc ccg ctc aag gag cag ggc cgt gag tgc tgc ctg tcc aag gac 1008 Ile Pro Pro Leu Lys Glu Gln Gly Arg Glu Cys Cys Leu Ser Lys Asp 325 330 335 gac gtc tac gac ttt ggg gcg ggg cgc cag gac ctc aat gcc agc ggc 1056 Asp Val Tyr Asp Phe Gly Ala Gly Arg Gln Asp Leu Asn Ala Ser Gly 340 345 350 ctc tgt gtc aac tgg aac cgt tac tac aat gtg tgc cgc acg ggc agc 1104 Leu Cys Val Asn Trp Asn Arg Tyr Tyr Asn Val Cys Arg Thr Gly Ser 355 360 365 gcc aac ccc cac aag ggt gcc atc aac ttt gac aac atc ggt tat gct 1152 Ala Asn Pro His Lys Gly Ala Ile Asn Phe Asp Asn Ile Gly Tyr Ala 370 375 380 tgg att gtc atc ttc cag gtg atc act ctg gaa ggc tgg gtg gag atc 1200 Trp Ile Val Ile Phe Gln Val Ile Thr Leu Glu Gly Trp Val Glu Ile 385 390 395 400 atg tac tac gtg atg gat gct cac tcc ttc tac aac ttc atc tac ttc 1248 Met Tyr Tyr Val Met Asp Ala His Ser Phe Tyr Asn Phe Ile Tyr Phe 405 410 415 atc ctg ctt atc ata agt gag ctc atc cac ctc gtc atg cct gac tgc 1296 Ile Leu Leu Ile Ile Ser Glu Leu Ile His Leu Val Met Pro Asp Cys 420 425 430 agc ttc agc aca gca cag tcc cca aaa tgt caa ggt gat tca ctc cca 1344 Ser Phe Ser Thr Ala Gln Ser Pro Lys Cys Gln Gly Asp Ser Leu Pro 435 440 445 gga gtc gct gct gaa tcc ctg ctg ctg cga gac tct agc tcc tca gtc 1392 Gly Val Ala Ala Glu Ser Leu Leu Leu Arg Asp Ser Ser Ser Ser Val 450 455 460 atc act gat gag gct gca gcc atg gag aac ctc ctg gcg ggc acc tcc 1440 Ile Thr Asp Glu Ala Ala Ala Met Glu Asn Leu Leu Ala Gly Thr Ser 465 470 475 480 aag ggg gat gaa agc tat ctg ctc agg ctg gcc ggc agc caa gtt cac 1488 Lys Gly Asp Glu Ser Tyr Leu Leu Arg Leu Ala Gly Ser Gln Val His 485 490 495 tcc cag gct cag caa atg ctg ggg agg ggg ctg ggc cct gaa agc ctg 1536 Ser Gln Ala Gln Gln Met Leu Gly Arg Gly Leu Gly Pro Glu Ser Leu 500 505 510 gaa act gga gag gag ccc cac tcg tgg agc cct cgg gcc aca agg aga 1584 Glu Thr Gly Glu Glu Pro His Ser Trp Ser Pro Arg Ala Thr Arg Arg 515 520 525 tgg gat ccc caa tgc caa cca ggg cag cct ctc ccc ctt cat ttc atg 1632 Trp Asp Pro Gln Cys Gln Pro Gly Gln Pro Leu Pro Leu His Phe Met 530 535 540 caa gca cag gtg ggc tcc ttc ttc atg atc aac ctg tgc ctc gtt gtc 1680 Gln Ala Gln Val Gly Ser Phe Phe Met Ile Asn Leu Cys Leu Val Val 545 550 555 560 ata gcg acc cag ttc tcg gag acc aag caa cgg gag cac cgg ctg atg 1728 Ile Ala Thr Gln Phe Ser Glu Thr Lys Gln Arg Glu His Arg Leu Met 565 570 575 ctg gag cag cgg cag cgc tac ctg tcc tcc agc acg gtg gcc agc tac 1776 Leu Glu Gln Arg Gln Arg Tyr Leu Ser Ser Ser Thr Val Ala Ser Tyr 580 585 590 gcc gag cct ggc gac tgc tac gag gag atc ttc cag tat gtc tgc cac 1824 Ala Glu Pro Gly Asp Cys Tyr Glu Glu Ile Phe Gln Tyr Val Cys His 595 600 605 atc ctg cgc aag gcc aag cgc cgc gcc ctg ggc ctc tac cag gcc ctg 1872 Ile Leu Arg Lys Ala Lys Arg Arg Ala Leu Gly Leu Tyr Gln Ala Leu 610 615 620 cag agc cgg cgc cag gcc ctg ggc ccg gag gcc ccg gcc ccc gcc aaa 1920 Gln Ser Arg Arg Gln Ala Leu Gly Pro Glu Ala Pro Ala Pro Ala Lys 625 630 635 640 cct ggg ccc cac gcc aag gag ccc cgg cac tac cct ctc aca gtc tgg 1968 Pro Gly Pro His Ala Lys Glu Pro Arg His Tyr Pro Leu Thr Val Trp 645 650 655 gaa tcg att ctt ggg agg caa gca gaa gaa tgc acg ctc aga gct gcc 2016 Glu Ser Ile Leu Gly Arg Gln Ala Glu Glu Cys Thr Leu Arg Ala Ala 660 665 670 gcc cac ccg tcc tcg ggt gcc agc cat cca ggc gtg ggc tcg gag gag 2064 Ala His Pro Ser Ser Gly Ala Ser His Pro Gly Val Gly Ser Glu Glu 675 680 685 gcc cca gag ctg tgc ccg caa cat agc ccc ctg gat gcg acg ccc cac 2112 Ala Pro Glu Leu Cys Pro Gln His Ser Pro Leu Asp Ala Thr Pro His 690 695 700 acc ctg gtg cag ccc atc ccc gcc acg ctg gct tcc gat ccc gcc agc 2160 Thr Leu Val Gln Pro Ile Pro Ala Thr Leu Ala Ser Asp Pro Ala Ser 705 710 715 720 tgc cct tgc tgc cag cat gag gac ggc cgg cgg ccc tcg ggc ctg ggc 2208 Cys Pro Cys Cys Gln His Glu Asp Gly Arg Arg Pro Ser Gly Leu Gly 725 730 735 agc acc gac tcg ggc cag gag ggc tcg ggc tcc ggg agc tcc gct ggt 2256 Ser Thr Asp Ser Gly Gln Glu Gly Ser Gly Ser Gly Ser Ser Ala Gly 740 745 750 ggc gag gac gag gcg gat ggg gac ggg gcc cgg agc agc gag gac gga 2304 Gly Glu Asp Glu Ala Asp Gly Asp Gly Ala Arg Ser Ser Glu Asp Gly 755 760 765 gcc tcc tca gaa ctg ggg aag gag gag gag gag gag gag cag gcg gat 2352 Ala Ser Ser Glu Leu Gly Lys Glu Glu Glu Glu Glu Glu Gln Ala Asp 770 775 780 ggg gcg gtc tgg ctg tgc ggg gat gtg tgg cgg gag acg cga gcc aag 2400 Gly Ala Val Trp Leu Cys Gly Asp Val Trp Arg Glu Thr Arg Ala Lys 785 790 795 800 ctg cgc ggc atc gtg gac agc aag tac ttc aac cgg ggc atc atg atg 2448 Leu Arg Gly Ile Val Asp Ser Lys Tyr Phe Asn Arg Gly Ile Met Met 805 810 815 gcc atc ctg gtc aac acc gtc agc atg ggc atc gag cac cac gag cag 2496 Ala Ile Leu Val Asn Thr Val Ser Met Gly Ile Glu His His Glu Gln 820 825 830 gcc agt gca gcg cag ccg ggc cgg gcc tgc ggg aga gga caa aat cca 2544 Ala Ser Ala Ala Gln Pro Gly Arg Ala Cys Gly Arg Gly Gln Asn Pro 835 840 845 gac ctt tgc atg acc ctc aag gcc cct tgt ctc tgt cac aac gtc cct 2592 Asp Leu Cys Met Thr Leu Lys Ala Pro Cys Leu Cys His Asn Val Pro 850 855 860 tca cca ggc cag ggt gtc ctg tcc cat cca gtg act cca ccc cat aca 2640 Ser Pro Gly Gln Gly Val Leu Ser His Pro Val Thr Pro Pro His Thr 865 870 875 880 gcc cca tgg cgc atg gag aca gga aag cag gga cac gga tgt gaa gaa 2688 Ala Pro Trp Arg Met Glu Thr Gly Lys Gln Gly His Gly Cys Glu Glu 885 890 895 gga cca gga caa cga agc agt gac atg ttt gcc ctg gag atg atc ctg 2736 Gly Pro Gly Gln Arg Ser Ser Asp Met Phe Ala Leu Glu Met Ile Leu 900 905 910 aag ctg gct gca ttt ggg ctc ttc gac tac ctg cgt aac ccc tac aac 2784 Lys Leu Ala Ala Phe Gly Leu Phe Asp Tyr Leu Arg Asn Pro Tyr Asn 915 920 925 atc ttc gac agc atc att gtc atc atc agc atc tgg gag atc gtg ggg 2832 Ile Phe Asp Ser Ile Ile Val Ile Ile Ser Ile Trp Glu Ile Val Gly 930 935 940 cag gcg gac ggt ggg ctg tcg gtg ctg cgg acc ttc cgg ctg ctg cgc 2880 Gln Ala Asp Gly Gly Leu Ser Val Leu Arg Thr Phe Arg Leu Leu Arg 945 950 955 960 gtg ctg aaa ctg gtg cgc ttc atg cct gcc ctg cgg cgc cag ctc gtg 2928 Val Leu Lys Leu Val Arg Phe Met Pro Ala Leu Arg Arg Gln Leu Val 965 970 975 gtg ctc atg aag acc atg gac aac gtg gcc acc ttc tgc atg ctg ctc 2976 Val Leu Met Lys Thr Met Asp Asn Val Ala Thr Phe Cys Met Leu Leu 980 985 990 atg ctc ttc atc ttc atc ttc agc atc ctt ggg atg cat att ttt ggc 3024 Met Leu Phe Ile Phe Ile Phe Ser Ile Leu Gly Met His Ile Phe Gly 995 1000 1005 tgc aag ttc agc ctc cgc acg gac act gga gac acg gtg ccc gac agg 3072 Cys Lys Phe Ser Leu Arg Thr Asp Thr Gly Asp Thr Val Pro Asp Arg 1010 1015 1020 aag aac ttc gac tcc ctg ctg tgg gcc atc gtc act gtg ttc cag atc 3120 Lys Asn Phe Asp Ser Leu Leu Trp Ala Ile Val Thr Val Phe Gln Ile 1025 1030 1035 1040 ctc acc cag gag gac tgg aac gtc gtt ctc tac aat ggc atg gcc tcc 3168 Leu Thr Gln Glu Asp Trp Asn Val Val Leu Tyr Asn Gly Met Ala Ser 1045 1050 1055 act tct ccc tgg gcc tcc ctc tac ttt gtc gcc ctc atg acc ttc ggc 3216 Thr Ser Pro Trp Ala Ser Leu Tyr Phe Val Ala Leu Met Thr Phe Gly 1060 1065 1070 aac tat gtg ctc ttc aac ctg ctg gtg gcc atc ctg gtg gag ggc ttc 3264 Asn Tyr Val Leu Phe Asn Leu Leu Val Ala Ile Leu Val Glu Gly Phe 1075 1080 1085 cag gcg gag gtg act gtg gtc ttg gca gag gaa gca ccc cca cag ggc 3312 Gln Ala Glu Val Thr Val Val Leu Ala Glu Glu Ala Pro Pro Gln Gly 1090 1095 1100 ctg cga aag act ggg cga ggg aga ggt ggc ctg gat ggg gga ggg ctg 3360 Leu Arg Lys Thr Gly Arg Gly Arg Gly Gly Leu Asp Gly Gly Gly Leu 1105 1110 1115 1120 caa ttc aaa ctt cta gca ggc aac cta tcc cta aag gag ggg gtt gct 3408 Gln Phe Lys Leu Leu Ala Gly Asn Leu Ser Leu Lys Glu Gly Val Ala 1125 1130 1135 gat gag gtg ggt gac gcc aat cgc tcc tac tcg gac gag gac cag agc 3456 Asp Glu Val Gly Asp Ala Asn Arg Ser Tyr Ser Asp Glu Asp Gln Ser 1140 1145 1150 tca tcc aac ata gaa gag ttt gat aag ctc cag gaa ggc ctg gac agc 3504 Ser Ser Asn Ile Glu Glu Phe Asp Lys Leu Gln Glu Gly Leu Asp Ser 1155 1160 1165 agc gga gat ccc aag ctc tgc cca atc ccc atg acc ccc aat ggg cac 3552 Ser Gly Asp Pro Lys Leu Cys Pro Ile Pro Met Thr Pro Asn Gly His 1170 1175 1180 ctg gac ccc agt ctc cca ctg ggt ggg cac cta ggt cct gct ggg gct 3600 Leu Asp Pro Ser Leu Pro Leu Gly Gly His Leu Gly Pro Ala Gly Ala 1185 1190 1195 1200 gcg gga cct gcc ccc cga ctc tca ctg cag ccg gac ccc atg ctg gtg 3648 Ala Gly Pro Ala Pro Arg Leu Ser Leu Gln Pro Asp Pro Met Leu Val 1205 1210 1215 gcc ctg ggc tcc cga aag agc agc gtc atg tct cta ggg agg atg agc 3696 Ala Leu Gly Ser Arg Lys Ser Ser Val Met Ser Leu Gly Arg Met Ser 1220 1225 1230 tat gac cag cgc tcc ctg gtg ggt ggt ctt aga gcc aca gcg ggg gtg 3744 Tyr Asp Gln Arg Ser Leu Val Gly Gly Leu Arg Ala Thr Ala Gly Val 1235 1240 1245 cag gct gcc ttt ggg cac ctg gtg ccc cag ccg tgg gtg tgc ctg tgg 3792 Gln Ala Ala Phe Gly His Leu Val Pro Gln Pro Trp Val Cys Leu Trp 1250 1255 1260 ggc gct gac ccg aac ggg aac tcc ttc cag tcc agc tcc cgg agc tcc 3840 Gly Ala Asp Pro Asn Gly Asn Ser Phe Gln Ser Ser Ser Arg Ser Ser 1265 1270 1275 1280 tac tac ggg cca tgg ggc cgc agc gcg gcc tgg gcc agc cgt cgc tcc 3888 Tyr Tyr Gly Pro Trp Gly Arg Ser Ala Ala Trp Ala Ser Arg Arg Ser 1285 1290 1295 agc tgg aac agc ctc aag cac aag ccg ccg tcg gcg gag cat gag tcc 3936 Ser Trp Asn Ser Leu Lys His Lys Pro Pro Ser Ala Glu His Glu Ser 1300 1305 1310 ctg ctc tct gcg gag cgc ggc ggc ggc gcc cgg gtc tgc gag gtt gcc 3984 Leu Leu Ser Ala Glu Arg Gly Gly Gly Ala Arg Val Cys Glu Val Ala 1315 1320 1325 gcg gac gag ggg ccg ccg cgg gcc gca ccc ctg cac acc cca cac gcc 4032 Ala Asp Glu Gly Pro Pro Arg Ala Ala Pro Leu His Thr Pro His Ala 1330 1335 1340 cac cac gtt cat cac ggg ccc cat ctg gcg cac cgc cac cgc cac cac 4080 His His Val His His Gly Pro His Leu Ala His Arg His Arg His His 1345 1350 1355 1360 cgc cgg acg ctg tcc ctc gac aac agg gac tcg gtg gac ctg gcc gag 4128 Arg Arg Thr Leu Ser Leu Asp Asn Arg Asp Ser Val Asp Leu Ala Glu 1365 1370 1375 ctg gtg ccc gcg gtg ggc gcc cac ccc cgg gcc gcc tgg agg gcg gca 4176 Leu Val Pro Ala Val Gly Ala His Pro Arg Ala Ala Trp Arg Ala Ala 1380 1385 1390 ggc ccg gcc ccc ggg cat gag gac tgc aat ggc agg atg ccc agc atc 4224 Gly Pro Ala Pro Gly His Glu Asp Cys Asn Gly Arg Met Pro Ser Ile 1395 1400 1405 gcc aaa gac gtc ttc acc aag atg ggc gac cgc ggg gat cgc ggg gag 4272 Ala Lys Asp Val Phe Thr Lys Met Gly Asp Arg Gly Asp Arg Gly Glu 1410 1415 1420 gat gag gag gaa atc gac tac gtg agt ggg ggc ggg gcc gaa ggg gac 4320 Asp Glu Glu Glu Ile Asp Tyr Val Ser Gly Gly Gly Ala Glu Gly Asp 1425 1430 1435 1440 ctg acc ctg tgc ttc cgc gtc cgc aag atg atc gac gtc tat aag ccc 4368 Leu Thr Leu Cys Phe Arg Val Arg Lys Met Ile Asp Val Tyr Lys Pro 1445 1450 1455 gac tgg tgc gag gtc cgc gaa gac tgg tct gtc tac ctc ttc tct ccc 4416 Asp Trp Cys Glu Val Arg Glu Asp Trp Ser Val Tyr Leu Phe Ser Pro 1460 1465 1470 gag aac agg ctc agg gat ctg ggc tgg gta agc ctc gag tgc cag gga 4464 Glu Asn Arg Leu Arg Asp Leu Gly Trp Val Ser Leu Glu Cys Gln Gly 1475 1480 1485 aag gtg ggt gac ctc gtg gtg tgg gtg tat ggt cag agg agg cag cgc 4512 Lys Val Gly Asp Leu Val Val Trp Val Tyr Gly Gln Arg Arg Gln Arg 1490 1495 1500 cag acc att att gcc cac aaa ctc ttc gac tac gtc gtc ctg gcc ttc 4560 Gln Thr Ile Ile Ala His Lys Leu Phe Asp Tyr Val Val Leu Ala Phe 1505 1510 1515 1520 atc ttt ctc aac tgc atc acc atc gcc ctg gag cgg cct cag atc gag 4608 Ile Phe Leu Asn Cys Ile Thr Ile Ala Leu Glu Arg Pro Gln Ile Glu 1525 1530 1535 gcc ggc agc acc gaa cgc atc ttt ctc acc gtg tcc aac tac atc ttc 4656 Ala Gly Ser Thr Glu Arg Ile Phe Leu Thr Val Ser Asn Tyr Ile Phe 1540 1545 1550 acg gcc atc ttc gtg ggc gag atg aca ttg aag gta gtc tcg ctg ggc 4704 Thr Ala Ile Phe Val Gly Glu Met Thr Leu Lys Val Val Ser Leu Gly 1555 1560 1565 ctg tac ttc ggc gag cag gcg tac cta cgc agc agc tgg aac gtg ctg 4752 Leu Tyr Phe Gly Glu Gln Ala Tyr Leu Arg Ser Ser Trp Asn Val Leu 1570 1575 1580 gat ggc ttt ctt gtc ttc gtg tcc atc atc gac atc gtg gtg tcc ctg 4800 Asp Gly Phe Leu Val Phe Val Ser Ile Ile Asp Ile Val Val Ser Leu 1585 1590 1595 1600 gcc tca gcc ggg gga gcc aag atc ttg ggg gtc ctc cga gtc ttg cgg 4848 Ala Ser Ala Gly Gly Ala Lys Ile Leu Gly Val Leu Arg Val Leu Arg 1605 1610 1615 ctc ctg cgc acc cta cgc ccc ctg cgt gtc atc agc cgg gcg ccg ggc 4896 Leu Leu Arg Thr Leu Arg Pro Leu Arg Val Ile Ser Arg Ala Pro Gly 1620 1625 1630 ctg aag ctg gtg gtg gag aca ctc atc tcc tcc ctc aag ccc atc ggc 4944 Leu Lys Leu Val Val Glu Thr Leu Ile Ser Ser Leu Lys Pro Ile Gly 1635 1640 1645 aac atc gtg ctc atc tgc tgt gcc ttc ttc atc atc ttt ggc atc ctg 4992 Asn Ile Val Leu Ile Cys Cys Ala Phe Phe Ile Ile Phe Gly Ile Leu 1650 1655 1660 gga gtg cag ctc ttc aag ggc aag ttc tac cac tgt ctg ggc gtg gac 5040 Gly Val Gln Leu Phe Lys Gly Lys Phe Tyr His Cys Leu Gly Val Asp 1665 1670 1675 1680 acc cgc aac atc acc aac cgc tcg gac tgc atg gcc gcc aac tac cgc 5088 Thr Arg Asn Ile Thr Asn Arg Ser Asp Cys Met Ala Ala Asn Tyr Arg 1685 1690 1695 tgg gtc cat cac aaa tac aac ttc gac aac ctg ggc cag gct ctg atg 5136 Trp Val His His Lys Tyr Asn Phe Asp Asn Leu Gly Gln Ala Leu Met 1700 1705 1710 tcc ctc ttt gtc ctg gca tcc aag gat ggt tgg gtg aac atc atg tac 5184 Ser Leu Phe Val Leu Ala Ser Lys Asp Gly Trp Val Asn Ile Met Tyr 1715 1720 1725 aat gga ctg gat gct gtt gct gtg gac cag cag cct gtg acc aac cac 5232 Asn Gly Leu Asp Ala Val Ala Val Asp Gln Gln Pro Val Thr Asn His 1730 1735 1740 aac ccc tgg atg ctg ctg tac ttc atc tcc ttc ctg ctc atc gtc agc 5280 Asn Pro Trp Met Leu Leu Tyr Phe Ile Ser Phe Leu Leu Ile Val Ser 1745 1750 1755 1760 ttc ttt gtg ctc aac atg ttt gtg ggt gtc gtg gtg gag aac ttc cac 5328 Phe Phe Val Leu Asn Met Phe Val Gly Val Val Val Glu Asn Phe His 1765 1770 1775 aag tgc cgg cag cac cag gag gct gaa gag gca cgg cgg cgt gag gag 5376 Lys Cys Arg Gln His Gln Glu Ala Glu Glu Ala Arg Arg Arg Glu Glu 1780 1785 1790 aag cgg ctg cgg cgc ctg gag aag aag cgc cgg aag gcc cag cgg ctg 5424 Lys Arg Leu Arg Arg Leu Glu Lys Lys Arg Arg Lys Ala Gln Arg Leu 1795 1800 1805 ccc tac tat gcc acc tat tgt cac acc cgg ctg ctc atc cac tcc atg 5472 Pro Tyr Tyr Ala Thr Tyr Cys His Thr Arg Leu Leu Ile His Ser Met 1810 1815 1820 tgc acc agc cac tac ctg gac atc ttc atc acc ttc atc atc tgc ctc 5520 Cys Thr Ser His Tyr Leu Asp Ile Phe Ile Thr Phe Ile Ile Cys Leu 1825 1830 1835 1840 aac gtg gtc acc atg tcc ctg gag cac tac aat cag ccc acg 5562 Asn Val Val Thr Met Ser Leu Glu His Tyr Asn Gln Pro Thr 1845 1850 19 1853 PRT Human 19 Phe Phe Val Ser Ala Asn Pro Trp Val Ser Phe Thr Ser Phe Asp Leu 1 5 10 15 Asn Val Ala Asn Met Asp Asn Phe Phe Ala Pro Val Phe Thr Met Gly 20 25 30 Lys Tyr Tyr Thr Gln Gly Asp Lys Val Leu Met Pro Leu Ala Ile Gln 35 40 45 Ala Leu Lys Gln Leu Met Phe Lys Leu Val Ala Thr Val Ala Arg Thr 50 55 60 His Ala Thr Pro Ser His Ile Thr Gly Gly Pro Gly Thr Gly Met His 65 70 75 80 Thr Gly Thr Phe Gln Glu Gly Ala Glu Pro Gly Ser Ser Gln His Pro 85 90 95 Glu Ala Gln Ala Thr Tyr Thr Ala Gly Cys Thr Pro Ala Pro Thr Gly 100 105 110 Asp Pro Thr Cys Cys Phe Val Leu Asp Leu Val Cys Thr Trp Phe Glu 115 120 125 Cys Val Ser Met Leu Val Ile Leu Leu Asn Cys Val Thr Leu Gly Met 130 135 140 Tyr Gln Pro Cys Asp Asp Met Asp Cys Leu Ser Asp Arg Cys Lys Ile 145 150 155 160 Leu Gln Val Phe Asp Asp Phe Ile Phe Ile Phe Phe Ala Met Glu Met 165 170 175 Val Leu Lys Met Val Ala Leu Gly Ile Phe Gly Lys Lys Cys Tyr Leu 180 185 190 Gly Asp Thr Trp Asn Arg Leu Asp Phe Phe Ile Val Met Ala Gly Asn 195 200 205 Ile Asn Leu Ser Ala Ile Arg Thr Val Arg Val Leu Arg Pro Leu Lys 210 215 220 Ala Ile Asn Arg Val Pro Ser Met Arg Ile Leu Val Asn Leu Leu Leu 225 230 235 240 Asp Thr Leu Pro Met Leu Gly Asn Val Leu Leu Leu Cys Phe Phe Val 245 250 255 Phe Phe Ile Phe Gly Ile Ile Gly Val Gln Leu Trp Ala Gly Leu Leu 260 265 270 Arg Asn Arg Cys Phe Leu Glu Glu Asn Phe Thr Ile Gln Gly Asp Val 275 280 285 Ala Leu Pro Pro Tyr Tyr Gln Pro Glu Glu Asp Asp Glu Met Pro Phe 290 295 300 Ile Cys Ser Leu Ser Gly Asp Asn Gly Ile Met Gly Cys His Glu Ile 305 310 315 320 Pro Pro Leu Lys Glu Gln Gly Arg Glu Cys Cys Leu Ser Lys Asp Asp 325 330 335 Val Tyr Asp Phe Gly Ala Gly Arg Gln Asp Leu Asn Ala Ser Gly Leu 340 345 350 Cys Val Asn Trp Asn Arg Tyr Tyr Asn Val Cys Arg Thr Gly Ser Ala 355 360 365 Asn Pro His Lys Gly Ala Ile Asn Phe Asp Asn Ile Gly Tyr Ala Trp 370 375 380 Ile Val Ile Phe Gln Val Ile Thr Leu Glu Gly Trp Val Glu Ile Met 385 390 395 400 Tyr Tyr Val Met Asp Ala His Ser Phe Tyr Asn Phe Ile Tyr Phe Ile 405 410 415 Leu Leu Ile Ile Ser Glu Leu Ile His Leu Val Met Pro Asp Cys Ser 420 425 430 Phe Ser Thr Ala Gln Ser Pro Lys Cys Gln Gly Asp Ser Leu Pro Gly 435 440 445 Val Ala Ala Glu Ser Leu Leu Leu Arg Asp Ser Ser Ser Ser Val Ile 450 455 460 Thr Asp Glu Ala Ala Ala Met Glu Asn Leu Leu Ala Gly Thr Ser Lys 465 470 475 480 Gly Asp Glu Ser Tyr Leu Leu Arg Leu Ala Gly Ser Gln Val His Ser 485 490 495 Gln Ala Gln Gln Met Leu Gly Arg Gly Leu Gly Pro Glu Ser Leu Glu 500 505 510 Thr Gly Glu Glu Pro His Ser Trp Ser Pro Arg Ala Thr Arg Arg Trp 515 520 525 Asp Pro Gln Cys Gln Pro Gly Gln Pro Leu Pro Leu His Phe Met Gln 530 535 540 Ala Gln Val Gly Ser Phe Phe Met Ile Asn Leu Cys Leu Val Val Ile 545 550 555 560 Ala Thr Gln Phe Ser Glu Thr Lys Gln Arg Glu His Arg Leu Met Leu 565 570 575 Glu Gln Arg Gln Arg Tyr Leu Ser Ser Ser Thr Val Ala Ser Tyr Ala 580 585 590 Glu Pro Gly Asp Cys Tyr Glu Glu Ile Phe Gln Tyr Val Cys His Ile 595 600 605 Leu Arg Lys Ala Lys Arg Arg Ala Leu Gly Leu Tyr Gln Ala Leu Gln 610 615 620 Ser Arg Arg Gln Ala Leu Gly Pro Glu Ala Pro Ala Pro Ala Lys Pro 625 630 635 640 Gly Pro His Ala Lys Glu Pro Arg His Tyr Pro Leu Thr Val Trp Glu 645 650 655 Ser Ile Leu Gly Arg Gln Ala Glu Glu Cys Thr Leu Arg Ala Ala Ala 660 665 670 His Pro Ser Ser Gly Ala Ser His Pro Gly Val Gly Ser Glu Glu Ala 675 680 685 Pro Glu Leu Cys Pro Gln His Ser Pro Leu Asp Ala Thr Pro His Thr 690 695 700 Leu Val Gln Pro Ile Pro Ala Thr Leu Ala Ser Asp Pro Ala Ser Cys 705 710 715 720 Pro Cys Cys Gln His Glu Asp Gly Arg Arg Pro Ser Gly Leu Gly Ser 725 730 735 Thr Asp Ser Gly Gln Glu Gly Ser Gly Ser Gly Ser Ser Ala Gly Gly 740 745 750 Glu Asp Glu Ala Asp Gly Asp Gly Ala Arg Ser Ser Glu Asp Gly Ala 755 760 765 Ser Ser Glu Leu Gly Lys Glu Glu Glu Glu Glu Glu Gln Ala Asp Gly 770 775 780 Ala Val Trp Leu Cys Gly Asp Val Trp Arg Glu Thr Arg Ala Lys Leu 785 790 795 800 Arg Gly Ile Val Asp Ser Lys Tyr Phe Asn Arg Gly Ile Met Met Ala 805 810 815 Ile Leu Val Asn Thr Val Ser Met Gly Ile Glu His His Glu Gln Ala 820 825 830 Ser Ala Ala Gln Pro Gly Arg Ala Cys Gly Arg Gly Gln Asn Pro Asp 835 840 845 Leu Cys Met Thr Leu Lys Ala Pro Cys Leu Cys His Asn Val Pro Ser 850 855 860 Pro Gly Gln Gly Val Leu Ser His Pro Val Thr Pro Pro His Thr Ala 865 870 875 880 Pro Trp Arg Met Glu Thr Gly Lys Gln Gly His Gly Cys Glu Glu Gly 885 890 895 Pro Gly Gln Arg Ser Ser Asp Met Phe Ala Leu Glu Met Ile Leu Lys 900 905 910 Leu Ala Ala Phe Gly Leu Phe Asp Tyr Leu Arg Asn Pro Tyr Asn Ile 915 920 925 Phe Asp Ser Ile Ile Val Ile Ile Ser Ile Trp Glu Ile Val Gly Gln 930 935 940 Ala Asp Gly Gly Leu Ser Val Leu Arg Thr Phe Arg Leu Leu Arg Val 945 950 955 960 Leu Lys Leu Val Arg Phe Met Pro Ala Leu Arg Arg Gln Leu Val Val 965 970 975 Leu Met Lys Thr Met Asp Asn Val Ala Thr Phe Cys Met Leu Leu Met 980 985 990 Leu Phe Ile Phe Ile Phe Ser Ile Leu Gly Met His Ile Phe Gly Cys 995 1000 1005 Lys Phe Ser Leu Arg Thr Asp Thr Gly Asp Thr Val Pro Asp Arg Lys 1010 1015 1020 Asn Phe Asp Ser Leu Leu Trp Ala Ile Val Thr Val Phe Gln Ile Leu 1025 1030 1035 1040 Thr Gln Glu Asp Trp Asn Val Val Leu Tyr Asn Gly Met Ala Ser Thr 1045 1050 1055 Ser Pro Trp Ala Ser Leu Tyr Phe Val Ala Leu Met Thr Phe Gly Asn 1060 1065 1070 Tyr Val Leu Phe Asn Leu Leu Val Ala Ile Leu Val Glu Gly Phe Gln 1075 1080 1085 Ala Glu Val Thr Val Val Leu Ala Glu Glu Ala Pro Pro Gln Gly Leu 1090 1095 1100 Arg Lys Thr Gly Arg Gly Arg Gly Gly Leu Asp Gly Gly Gly Leu Gln 1105 1110 1115 1120 Phe Lys Leu Leu Ala Gly Asn Leu Ser Leu Lys Glu Gly Val Ala Asp 1125 1130 1135 Glu Val Gly Asp Ala Asn Arg Ser Tyr Ser Asp Glu Asp Gln Ser Ser 1140 1145 1150 Ser Asn Ile Glu Glu Phe Asp Lys Leu Gln Glu Gly Leu Asp Ser Ser 1155 1160 1165 Gly Asp Pro Lys Leu Cys Pro Ile Pro Met Thr Pro Asn Gly His Leu 1170 1175 1180 Asp Pro Ser Leu Pro Leu Gly Gly His Leu Gly Pro Ala Gly Ala Ala 1185 1190 1195 1200 Gly Pro Ala Pro Arg Leu Ser Leu Gln Pro Asp Pro Met Leu Val Ala 1205 1210 1215 Leu Gly Ser Arg Lys Ser Ser Val Met Ser Leu Gly Arg Met Ser Tyr 1220 1225 1230 Asp Gln Arg Ser Leu Val Gly Gly Leu Arg Ala Thr Ala Gly Val Gln 1235 1240 1245 Ala Ala Phe Gly His Leu Val Pro Gln Pro Trp Val Cys Leu Trp Gly 1250 1255 1260 Ala Asp Pro Asn Gly Asn Ser Phe Gln Ser Ser Ser Arg Ser Ser Tyr 1265 1270 1275 1280 Tyr Gly Pro Trp Gly Arg Ser Ala Ala Trp Ala Ser Arg Arg Ser Ser 1285 1290 1295 Trp Asn Ser Leu Lys His Lys Pro Pro Ser Ala Glu His Glu Ser Leu 1300 1305 1310 Leu Ser Ala Glu Arg Gly Gly Gly Ala Arg Val Cys Glu Val Ala Ala 1315 1320 1325 Asp Glu Gly Pro Pro Arg Ala Ala Pro Leu His Thr Pro His Ala His 1330 1335 1340 His Val His His Gly Pro His Leu Ala His Arg His Arg His His Arg 1345 1350 1355 1360 Arg Thr Leu Ser Leu Asp Asn Arg Asp Ser Val Asp Leu Ala Glu Leu 1365 1370 1375 Val Pro Ala Val Gly Ala His Pro Arg Ala Ala Trp Arg Ala Ala Gly 1380 1385 1390 Pro Ala Pro Gly His Glu Asp Cys Asn Gly Arg Met Pro Ser Ile Ala 1395 1400 1405 Lys Asp Val Phe Thr Lys Met Gly Asp Arg Gly Asp Arg Gly Glu Asp 1410 1415 1420 Glu Glu Glu Ile Asp Tyr Val Ser Gly Gly Gly Ala Glu Gly Asp Leu 1425 1430 1435 1440 Thr Leu Cys Phe Arg Val Arg Lys Met Ile Asp Val Tyr Lys Pro Asp 1445 1450 1455 Trp Cys Glu Val Arg Glu Asp Trp Ser Val Tyr Leu Phe Ser Pro Glu 1460 1465 1470 Asn Arg Leu Arg Asp Leu Gly Trp Val Ser Leu Glu Cys Gln Gly Lys 1475 1480 1485 Val Gly Asp Leu Val Val Trp Val Tyr Gly Gln Arg Arg Gln Arg Gln 1490 1495 1500 Thr Ile Ile Ala His Lys Leu Phe Asp Tyr Val Val Leu Ala Phe Ile 1505 1510 1515 1520 Phe Leu Asn Cys Ile Thr Ile Ala Leu Glu Arg Pro Gln Ile Glu Ala 1525 1530 1535 Gly Ser Thr Glu Arg Ile Phe Leu Thr Val Ser Asn Tyr Ile Phe Thr 1540 1545 1550 Ala Ile Phe Val Gly Glu Met Thr Leu Lys Val Val Ser Leu Gly Leu 1555 1560 1565 Tyr Phe Gly Glu Gln Ala Tyr Leu Arg Ser Ser Trp Asn Val Leu Asp 1570 1575 1580 Gly Phe Leu Val Phe Val Ser Ile Ile Asp Ile Val Val Ser Leu Ala 1585 1590 1595 1600 Ser Ala Gly Gly Ala Lys Ile Leu Gly Val Leu Arg Val Leu Arg Leu 1605 1610 1615 Leu Arg Thr Leu Arg Pro Leu Arg Val Ile Ser Arg Ala Pro Gly Leu 1620 1625 1630 Lys Leu Val Val Glu Thr Leu Ile Ser Ser Leu Lys Pro Ile Gly Asn 1635 1640 1645 Ile Val Leu Ile Cys Cys Ala Phe Phe Ile Ile Phe Gly Ile Leu Gly 1650 1655 1660 Val Gln Leu Phe Lys Gly Lys Phe Tyr His Cys Leu Gly Val Asp Thr 1665 1670 1675 1680 Arg Asn Ile Thr Asn Arg Ser Asp Cys Met Ala Ala Asn Tyr Arg Trp 1685 1690 1695 Val His His Lys Tyr Asn Phe Asp Asn Leu Gly Gln Ala Leu Met Ser 1700 1705 1710 Leu Phe Val Leu Ala Ser Lys Asp Gly Trp Val Asn Ile Met Tyr Asn 1715 1720 1725 Gly Leu Asp Ala Val Ala Val Asp Gln Gln Pro Val Thr Asn His Asn 1730 1735 1740 Pro Trp Met Leu Leu Tyr Phe Ile Ser Phe Leu Leu Ile Val Ser Phe 1745 1750 1755 1760 Phe Val Leu Asn Met Phe Val Gly Val Val Val Glu Asn Phe His Lys 1765 1770 1775 Cys Arg Gln His Gln Glu Ala Glu Glu Ala Arg Arg Arg Glu Glu Lys 1780 1785 1790 Arg Leu Arg Arg Leu Glu Lys Lys Arg Arg Lys Ala Gln Arg Leu Pro 1795 1800 1805 Tyr Tyr Ala Thr Tyr Cys His Thr Arg Leu Leu Ile His Ser Met Cys 1810 1815 1820 Thr Ser His Tyr Leu Asp Ile Phe Ile Thr Phe Ile Ile Cys Leu Asn 1825 1830 1835 1840 Val Val Thr Met Ser Leu Glu His Tyr Asn Gln Pro Thr 1845 1850 20 567 DNA Human CDS (1)...(567) Human alpha-1 partial sequence 20 atg cgg atc ctg gtg aac ctg ctc ctg gac aca ctg ccc atg ctg ggg 48 Met Arg Ile Leu Val Asn Leu Leu Leu Asp Thr Leu Pro Met Leu Gly 1 5 10 15 aat gtc ctg ctg ctc tgc ttc ttt gtc ttc ttc acc ttt ggc atc ata 96 Asn Val Leu Leu Leu Cys Phe Phe Val Phe Phe Thr Phe Gly Ile Ile 20 25 30 ggt gtg cag ctc tgg gcg ggc ctg ctg cgt aac cgc tgc ttc ctg gag 144 Gly Val Gln Leu Trp Ala Gly Leu Leu Arg Asn Arg Cys Phe Leu Glu 35 40 45 gag aac ttc acc ata caa ggg gat gtg gcc ttg ccc cca tac tac cag 192 Glu Asn Phe Thr Ile Gln Gly Asp Val Ala Leu Pro Pro Tyr Tyr Gln 50 55 60 ccg gag gag gat gat gag atg ccc ttc atc tgc tcc ctg tcg ggc gac 240 Pro Glu Glu Asp Asp Glu Met Pro Phe Ile Cys Ser Leu Ser Gly Asp 65 70 75 80 aat ggg ata atg ggc tgc cat gag atc ccc ccg ctc aag gag cag ggc 288 Asn Gly Ile Met Gly Cys His Glu Ile Pro Pro Leu Lys Glu Gln Gly 85 90 95 cgt gag tgc tgc ctg tcc aag gac gac gtc tac gac ttt ggg gcg ggg 336 Arg Glu Cys Cys Leu Ser Lys Asp Asp Val Tyr Asp Phe Gly Ala Gly 100 105 110 cgc cag gac ctc aat gcc agc ggc ctc tgt gtc aac tgg aac cgt tac 384 Arg Gln Asp Leu Asn Ala Ser Gly Leu Cys Val Asn Trp Asn Arg Tyr 115 120 125 tac aat gtg tgc cgc acg ggc agc gcc aac ccc cac aag ggt gcc atc 432 Tyr Asn Val Cys Arg Thr Gly Ser Ala Asn Pro His Lys Gly Ala Ile 130 135 140 agc ttt gac aac atc ggt tat gct tgg att gtc atc ttc cag gtg atc 480 Ser Phe Asp Asn Ile Gly Tyr Ala Trp Ile Val Ile Phe Gln Val Ile 145 150 155 160 act ctg gaa ggc tgg gtg gcg atc atg tac tac gtg atg gat gct ctc 528 Thr Leu Glu Gly Trp Val Ala Ile Met Tyr Tyr Val Met Asp Ala Leu 165 170 175 tcc ttc tac aac ttc gtc tac ttc atc ctg ctt atc ata 567 Ser Phe Tyr Asn Phe Val Tyr Phe Ile Leu Leu Ile Ile 180 185 21 188 PRT Human 21 Arg Ile Leu Val Asn Leu Leu Leu Asp Thr Leu Pro Met Leu Gly Asn 1 5 10 15 Val Leu Leu Leu Cys Phe Phe Val Phe Phe Thr Phe Gly Ile Ile Gly 20 25 30 Val Gln Leu Trp Ala Gly Leu Leu Arg Asn Arg Cys Phe Leu Glu Glu 35 40 45 Asn Phe Thr Ile Gln Gly Asp Val Ala Leu Pro Pro Tyr Tyr Gln Pro 50 55 60 Glu Glu Asp Asp Glu Met Pro Phe Ile Cys Ser Leu Ser Gly Asp Asn 65 70 75 80 Gly Ile Met Gly Cys His Glu Ile Pro Pro Leu Lys Glu Gln Gly Arg 85 90 95 Glu Cys Cys Leu Ser Lys Asp Asp Val Tyr Asp Phe Gly Ala Gly Arg 100 105 110 Gln Asp Leu Asn Ala Ser Gly Leu Cys Val Asn Trp Asn Arg Tyr Tyr 115 120 125 Asn Val Cys Arg Thr Gly Ser Ala Asn Pro His Lys Gly Ala Ile Ser 130 135 140 Phe Asp Asn Ile Gly Tyr Ala Trp Ile Val Ile Phe Gln Val Ile Thr 145 150 155 160 Leu Glu Gly Trp Val Ala Ile Met Tyr Tyr Val Met Asp Ala Leu Ser 165 170 175 Phe Tyr Asn Phe Val Tyr Phe Ile Leu Leu Ile Ile 180 185 22 567 DNA Rat CDS (1)...(567) Rat alpha-1 partial sequence 22 atg cgg atc ctg gtg aac ctg ctg ctc gac acg ctg ccc atg ctg ggg 48 Met Arg Ile Leu Val Asn Leu Leu Leu Asp Thr Leu Pro Met Leu Gly 1 5 10 15 aac gtg ctc ctg ctc tgt ttc ttc gtc ttc ttc atc ttc ggc atc att 96 Asn Val Leu Leu Leu Cys Phe Phe Val Phe Phe Ile Phe Gly Ile Ile 20 25 30 ggc gtg cag ctc tgg gca ggc ctg cta cgg aac cgc tgc ttc ctg gaa 144 Gly Val Gln Leu Trp Ala Gly Leu Leu Arg Asn Arg Cys Phe Leu Glu 35 40 45 gaa aac ttc acc ata caa ggg gat gtg gcc ctg ccc cct tat tac caa 192 Glu Asn Phe Thr Ile Gln Gly Asp Val Ala Leu Pro Pro Tyr Tyr Gln 50 55 60 cca gag gag gat gac gag atg ccc ttt atc tgc tcc ctg act ggg gac 240 Pro Glu Glu Asp Asp Glu Met Pro Phe Ile Cys Ser Leu Thr Gly Asp 65 70 75 80 aat ggc atc atg ggc tgc cac gag atc ccc cca ctg aag gag cag ggc 288 Asn Gly Ile Met Gly Cys His Glu Ile Pro Pro Leu Lys Glu Gln Gly 85 90 95 cgg gaa tgc tgc ctg tcc aaa gat gat gtg tat gac ttc ggg gcg ggg 336 Arg Glu Cys Cys Leu Ser Lys Asp Asp Val Tyr Asp Phe Gly Ala Gly 100 105 110 cgc cag gac ctc aac gcc agc ggt ctg tgc gtc aac tgg aac cgc tac 384 Arg Gln Asp Leu Asn Ala Ser Gly Leu Cys Val Asn Trp Asn Arg Tyr 115 120 125 tac aac gtc tgc cgc acg ggc aac gcc aac cct cac aag ggc gcc atc 432 Tyr Asn Val Cys Arg Thr Gly Asn Ala Asn Pro His Lys Gly Ala Ile 130 135 140 aac ttt gac aac att ggc tat gcc tgg att gtg att ttc cag gtg atc 480 Asn Phe Asp Asn Ile Gly Tyr Ala Trp Ile Val Ile Phe Gln Val Ile 145 150 155 160 act ctg gaa ggc tgg gtg gag atc atg tac tat gtg atg gac gca cat 528 Thr Leu Glu Gly Trp Val Glu Ile Met Tyr Tyr Val Met Asp Ala His 165 170 175 tct ttc tac aac ttc atc tac ttc atc ctg ctt atc ata 567 Ser Phe Tyr Asn Phe Ile Tyr Phe Ile Leu Leu Ile Ile 180 185 23 188 PRT Rat 23 Arg Ile Leu Val Asn Leu Leu Leu Asp Thr Leu Pro Met Leu Gly Asn 1 5 10 15 Val Leu Leu Leu Cys Phe Phe Val Phe Phe Ile Phe Gly Ile Ile Gly 20 25 30 Val Gln Leu Trp Ala Gly Leu Leu Arg Asn Arg Cys Phe Leu Glu Glu 35 40 45 Asn Phe Thr Ile Gln Gly Asp Val Ala Leu Pro Pro Tyr Tyr Gln Pro 50 55 60 Glu Glu Asp Asp Glu Met Pro Phe Ile Cys Ser Leu Thr Gly Asp Asn 65 70 75 80 Gly Ile Met Gly Cys His Glu Ile Pro Pro Leu Lys Glu Gln Gly Arg 85 90 95 Glu Cys Cys Leu Ser Lys Asp Asp Val Tyr Asp Phe Gly Ala Gly Arg 100 105 110 Gln Asp Leu Asn Ala Ser Gly Leu Cys Val Asn Trp Asn Arg Tyr Tyr 115 120 125 Asn Val Cys Arg Thr Gly Asn Ala Asn Pro His Lys Gly Ala Ile Asn 130 135 140 Phe Asp Asn Ile Gly Tyr Ala Trp Ile Val Ile Phe Gln Val Ile Thr 145 150 155 160 Leu Glu Gly Trp Val Glu Ile Met Tyr Tyr Val Met Asp Ala His Ser 165 170 175 Phe Tyr Asn Phe Ile Tyr Phe Ile Leu Leu Ile Ile 180 185 24 31 PRT Human 24 Val Ile Ser Leu Glu Gly Trp Thr Asp Ile Met Tyr Tyr Val Gln Asp 1 5 10 15 Ala His Ser Phe Trp Asn Trp Ile Tyr Phe Val Leu Leu Ile Val 20 25 30 25 31 PRT C. elegans 25 Val Ile Thr Leu Glu Gly Trp Val Glu Ile Met Tyr Tyr Val Met Asp 1 5 10 15 Ala His Ser Phe Tyr Asn Phe Ile Tyr Phe Ile Leu Leu Ile Ile 20 25 30 26 23 PRT Human 26 Asn Ile Asn Leu Thr Ala Ile Arg Thr Val Arg Val Leu Arg Pro Leu 1 5 10 15 Arg Ala Val Asn Arg Ile Pro 20 27 23 PRT C. elegans 27 Asn Ile Asn Leu Ser Ala Ile Arg Thr Val Arg Val Leu Arg Pro Leu 1 5 10 15 Lys Ala Ile Asn Arg Val Pro 20 28 19 PRT Human 28 Met Ala Val Ile Met Ile Asn Cys Val Thr Leu Gly Met Tyr Arg Pro 1 5 10 15 Cys Glu Asp 29 19 PRT C. elegans 29 Met Leu Val Ile Leu Leu Asn Cys Val Thr Leu Gly Met Tyr Gln Pro 1 5 10 15 Cys Asp Asp 30 23 PRT Human 30 Leu Thr Ala Ile Arg Thr Val Arg Val Leu Arg Pro Leu Arg Ala Val 1 5 10 15 Asn Arg Ile Pro Ser Met Arg 20 31 23 PRT C. elegans 31 Ile Lys Ser Leu Arg Thr Leu Arg Ala Leu Arg Pro Leu Arg Ala Leu 1 5 10 15 Ser Arg Phe Glu Gly Met Arg 20 32 41 PRT Human 32 Pro Thr Ile Ile Arg Val Met Arg Val Leu Arg Ile Ala Arg Val Leu 1 5 10 15 Lys Leu Leu Lys Met Ala Lys Gly Ile Arg Ser Leu Leu Asp Thr Val 20 25 30 Gly Glu Ala Leu Pro Gln Val Gly Asn 35 40 33 40 PRT C. elegans VARIANT (1)...(40) Xaa = Any Amino Acid 33 Pro Thr Leu Xaa Arg Val Ile Arg Leu Ala Arg Ile Gly Arg Ile Leu 1 5 10 15 Arg Leu Ile Lys Ala Lys Gly Ile Arg Thr Leu Leu Phe Ala Leu Met 20 25 30 Met Ser Leu Pro Ala Leu Phe Asn 35 40 

1. An isolated DNA fragment comprising a sequence of nucleotides that encodes a calcium channel, wherein the sequence of nucleotides is selected from sequences of nucleotides encoding a protein including the sequence of amino acids set forth in SEQ ID. No. 19, and sequences of nucleotides that hybridize under non-stringent conditions to DNA encoding a protein including the sequence set forth in SEQ ID No.
 19. 2. The DNA fragment of claim 1, wherein the sequence of nucleotides is selected from sequences of nucleotides encoding a protein including the sequence of amino acids set forth in SEQ ID. No. 18, and sequences of nucleotides that hybridize under non-stringent conditions to DNA encoding a protein including the sequence set forth in SEQ ID No.
 18. 3. The DNA fragment of claim 1, wherein the calcium channel is a human neuronal calcium channel.
 4. A vertebrate expression vector containing the DNA fragment of claim
 1. 5. A vertebrate expression vector containing the DNA fragment of claim
 2. 6. A eukaryotic cell transiently or stably transformed with the vertebrate expression vector of claim 4, said cell expressing the calcium channel encoded by the DNA fragment.
 7. The eukaryotic cell of claim 6, wherein the cell is further transformed with and expresses an α2δ or a β calcium channel subunit, or both.
 8. A eukaryotic cell transiently or stably transformed with a heterologous DNA fragment according to claim 1, said cell expressing the calcium channel encoded by the DNA fragment.
 9. The eukaryotic cell of claim 8, wherein the cell is further transformed with and expresses an α2δ or a β calcium channel subunit, or both.
 10. A method for the production of the α-_(1I) protein of an animal cell calcium channel comprising, culturing the cell of claim 6 under conditions whereby the DNA encoding the calcium channel subunit is expressed and the α-_(1I) subunit is produced.
 11. A process for producing the eukaryotic cell that is transiently or stably transformed and expresses a calcium channel, comprising the step of introducing RNA or DNA having a sequence selected from among sequences that encode a protein including the sequence of amino acids set forth in SEQ ID. No. 19, and sequences of nucleotides that hybridize under non-stringent conditions to DNA encoding a protein including the sequence set forth in SEQ ID No. 19 and RNA or DNA encoding an α2δ or a β calcium channel subunit into a cell.
 12. A method of identifying compounds capable of acting as agonists or antagonists for the α-_(1I) calcium channel, comprising contacting a cell according to claim 4 with an agent to be tested, and evaluating the interaction, if any, between the agent to be tested and the calcium channel.
 13. An isolated DNA fragment comprising a sequence of nucleotides that encodes a human calcium channel subunit, wherein the sequence of nucleotides is selected from sequences of nucleotides including the sequence set forth in SEQ ID No.
 17. 14. An isolated DNA fragment having the sequence given by SEQ ID No.
 19. 15. A method for mapping the distribution of calcium channel subunits within a tissue sample comprising the steps of exposing the tissue to a reagent comprising a directly or indirectly detectable label coupled to a DNA fragment comprising a sequence selected from among those sequences given by SEQ ID Nos. 13-20, and detecting reagent that has bound to the tissue. 